Fungicides

ABSTRACT

Use of compounds of general formula (I) or salts thereof as phytopathogenic fungicides wherein the various radicals and substituents are as defined in the description, pesticidal compositions containing them and method for combatting pests which comprises applying these.

This invention relates to compounds having fungicidal activity.

As a prior art including compounds similar to the compound according to the invention in the chemical structure, there have hitherto been known the specification of EP0288976. It discloses that the compounds protect plants against attack by harmful microorganisms, for example phytopathogenic fungi, bacteria and viruses. Nevertheless, nothing is written about an eventual action of this sort of compounds on the metabolism phtyopatogen organisms.

In a first aspect the invention provides the use of a compound of general formula I or salts thereof as phytopathogenic fungicides

where

-   A¹ is 3-Cl-5-CF₃-2-pyridyl; -   A² is optionally substituted heterocyclyl or optionally substituted     carbocyclyl (A² is preferably phenyl, cyclohexyl, cyclopropyl or     heterocyclyl, each of which may be substituted); excepted when L is     —N(R₃)N(R₄)C(═O) or —CH₂OCH₂—, then A₂ can not contain any     heterocyclyl containing N or O; -   L is a 3-atom linker selected from the list: —CH(R¹)N(R³)CH(R²)—,     —N(R³)N(R⁴)C(═X)—, —C(═X)N(R³)CH(R¹)—, —CH(R¹)OC(═X)—,     —CH(R¹)OCH(R²)—, —N(R³)C(═X)N(R⁴)—, —C(R¹)═C(R²)C(═X)—,     —CH(R¹)N═C(R²)—, —O—N═C(R¹)—, —O—N(R³)C(═X)—, —N(R³)N(R⁴)CH(R¹),     —N(R³)C(Y)═N—, —N═C(Y)—N(R³)—, —C(═X)—N(R³)N(R⁴)—, —C(Y)═N—N(R⁴)—     and —N(R³)CH(R¹)C(═X)—; wherein A¹ is attached to the left hand side     of linker L (L is preferably selected from the list:     —CH(R¹)N(R³)CH(R²)—, —N(R³)N(R⁴)C(═X)—, —C(═X)N(R³)CH(R¹),     —CH(R¹)OC(═X)—, —CH(R¹)OCH(R²)—, —N(R³)C(═X)N(R⁴)—,     —C(R¹)═C(R²)C(═X)—, —CH(R¹)N═C(R²)—, —O—N═C(R¹)—, —O—N(R³)C(═X)—); -   where R¹and R², which may be the same or different, are R^(b),     cyano, nitro, halogen, —OR^(b), —SR^(b) or optionally substituted     amino (R¹ and R² are preferably hydrogen, acyl, optionally     substituted alkyl, cyano or optionally substituted phenyl);     -   R³ and R⁴, which may be the same or different, are R^(b), cyano         or nitro (R³ and R⁴ are preferably hydrogen, acyl or optionally         substituted alkyl);     -   or any R¹, R², R³ or R⁴ group, together with the interconnecting         atoms, can form a 5- or 6-membered ring with any other R¹, R²,         R³ or R⁴, or any R¹, R², R³ or R⁴ group, together with the         interconnecting atoms can form a 5- or 6-membered ring with A²; -   X is oxygen, sulfur, N—OR^(b), N—R^(b) or N—N(R^(b))₂ (X is     preferably oxygen or sulfur); and -   Y is halogen, —OR^(b), —SR^(b), —N(R^(b))₂, —NR^(b)(OR^(b)) or     —NR^(b)N(R^(b))₂; -   wherein R^(b) is alkyl, alkenyl, alkynyl, carbocyclyl or     heterocyclyl, each of which may be substituted; or hydrogen or acyl,     or two adjacent R^(b) groups together with the nitrogen atom to     which they are attached may form a 5- or 6-membered ring.

Preferred substituents on the 2-pyridyl group (A¹) are halogen, hydroxy, cyano, nitro, SF₅, trialkylsilyl, optionally substituted amino, acyl, or a group —R^(a), —OR^(a) or —SR^(a), or a group —C(R^(a))═N-Q, where Q is —R^(a), —OR^(a), —SR^(a) or optionally substituted amino, wherein R^(a) is alkyl, alkenyl, alkynyl, carbocyclyl or heterocyclyl, each of which may be substituted; or two adjacent substituents together with the atoms to which they are attached form an optionally substituted ring which can contain up to 3 hetero atoms. Especially preferred substituents are alkoxy, alkyl, cyano, halogen, nitro, alkoxycarbonyl; alkylsulfinyl, alkylsulfonyl and trifluoromethyl, particularly chlorine and trifluoromethyl.

Preferably, the 2-pyridyl group is substituted at the 3 and/or 5 position.

The invention also includes any of the compounds specifically exemplified hereinafter.

Any alkyl group may be straight or branched and is preferably of 1 to 10 carbon atoms, especially 1 to 7 and particularly 1 to 5 carbon atoms.

Any alkenyl or alkynyl group may be straight or branched and is preferably of 2 to 7 carton atoms and may contain up to 3 double or triple bonds which may be conjugated, for example vinyl, allyl, butadienyl or propargyl.

Any carbocyclyl group may be saturated, unsaturated or aromatic, and contain 3 to 8 ring-atoms. Preferred saturated carbocyclyl groups are cyclopropyl, cyclopentyl or cyclohexyl. Preferred unsaturated carbocyclyl groups contain up to 3 double bonds. A preferred aromatic carbocyclyl group is phenyl. The term carbocylic should be similarly construed. In addition, the term carbocyclyl includes any fused combination of carbocyclyl groups, for example naphthyl, phenanthryl, indanyl and indenyl.

Any heterocyclyl group may be saturated, unsaturated or aromatic, and contain 5 to 7 ring-atoms up to 4 of which may be hetero-atoms such as nitrogen, oxygen and sulfur. Examples of heterocyclyl groups are furyl, thienyl, pyrrolyl, pyrrolinyl, pyrrolidinyl, imidazolyl, dioxolanyl, oxazolyl, thiazolyl, imidazolyl, imidazolinyl, imidazolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, isoxazolyl, isothiazolyl, oxadiazolyl, triazolyl, thiadiazolyl, pyranyl, pyridyl, piperidinyl, dioxanyl, morpholino, dithianyl, thiomorpholino, pyridazinyl, pyrimidinyl, pyrazinyl, piperazinyl, sulfolanyl, tetrazolyl, triazinyl, azepinyl, oxazepinyl, thiazepinyl, diazepinyl and thiazolinyl. In addition, the term heterocyclyl includes fused heterocyclyl groups, for example benzimidazolyl, benzoxazolyl, imidazopyridinyl, benzoxazinyl, benzothiazinyl, oxazolopyridinyl, benzofuranyl, quinolinyl, quinazolinyl, quinoxalinyl, dihydroquinazolinyl, benzothiazolyl, phthalimido, benzofuranyl, benzodiazepinyl, indolyl and isoindolyl. The term heterocyclic should be similarly construed.

Any alkyl, alkenyl, alkynyl, carbocyclyl or heterocyclyl group, when substituted, may be substituted by one or more substituents, which may be the same or different, and may be selected from the list: hydroxy; mercapto; azido; nitro; halogen; cyano; acyl; optionally substituted amino; optionally substituted carbocyclyl; optionally substituted heterocyclyl; cyanato; thiocyanato; —SF₅; —OR^(a); —SR^(a) and —Si(R^(a))₃, where R^(a) is alkyl, alkenyl, alkynyl, carbocyclyl or heterocyclyl, each of which may be substituted. In the case of any carbocyclyl or heterocyclyl group the list includes additionally: alkyl, alkenyl and alkynyl, each of which may be substituted. Preferred substituents on any alkyl, alkenyl or alkynyl group are alkoxy, haloalkoxy or alkylthio, each containing 1 to 5 carbon atoms; halogen; or optionally substituted phenyl. Preferred substituents on any carbocyclyl or heterocyclyl group are alkyl, haloalkyl, alkoxy, haloalkoxy or alkylthio, each containing 1 to 5 carbon atoms; halogen; or optionally substituted phenyl.

In the case of any alkyl group or any unsaturated ring-carbon in any carbocyclyl or heterocyclyl group the list includes a divalent group such as oxo or imino, which may be substituted by optionally substituted amino, R^(a) or —OR^(a). Preferred groups are oxo, imino, alkylimino, oximino, alkyloximino or hydrazono.

Any amino group, when substituted and where appropriate, may be substituted by one or two substituents which may be the same or different, selected from the list: optionally substituted alkyl, optionally substituted amino, —OR⁸ and acyl groups. Alternatively two substituents together with the nitrogen to which they are attached may form a heterocyclyl group, preferably a 5 to 7-membered heterocyclyl group, which may be substituted and may contain other hetero atoms, for example morpholino, thiomorpholino or piperidinyl.

The term acyl includes the residues of sulfur and phosphorus-containing acids as well as carboxylic acids. Typically the residues are covered by the general formulae —C(═X^(a))R^(c), —S(O)_(p)R^(c) and —P(═X^(a))(OR^(a))(OR^(a)), where appropriate X^(a) is O or S, R^(c) is as defined for R^(a), —OR^(a), —SR^(a), optionally substituted amino or acyl; and p is 1 or 2. Preferred groups are —C(═O)R^(d), —C(═S)R^(d), and —S(O)_(p)R^(d) where R^(d) is alkyl, C₁ to C₅ alkoxy, C₁ to C₅ alkylthio, phenyl, heterocyclyl or amino, each of which may be substituted.

Complexes of compounds of the invention are usually formed from a salt of formula MAn₂, in which M is a divalent metal cation, e.g. copper, manganese, cobalt, nickel, iron or zinc and An is an anion, e.g. chloride, nitrate or sulfate.

In cases where the compounds of the invention exist as the E and Z isomers, the invention includes individual isomers as well as mixtures thereof.

In cases where compounds of the invention exist as tautomeric isomers, the invention includes individual tautomers as well as mixtures thereof.

In cases where the compounds of the invention exist as optical isomers, the invention includes individual isomers as well as mixtures thereof.

The compounds of the invention have activity as fungicides, especially against fungal diseases of plants, e.g. mildews and particularly cereal powdery mildew (Erysiphe graminis) and vine downy mildew (Plasmopara viticola), rice blast (Pyricularia oryzae), cereal eyespot (Pseudocercosporella herpotrichoides), rice sheath blight (Pellicularia sasakii), grey mould (Botryis cinerea), damping off (Rhizoctonia solani), wheat brown rust (Puccinia recondita), late tomato or potato blight (Phytophthora infestans), apple scab (Venturia inaequalis), and glume blotch (Leptosphaeria nodorum). Other fungi against which the compounds may be active include other powdery mildews, other rusts, and other general pathogens of Deuteromycete, Ascomycete, Phycomycete and Basidomycete origin.

The invention thus also provides a method of combating fungi at a locus infested or liable to be infested therewith, which comprises applying to the locus a compound of formula I.

The invention also provides an agricultural composition comprising a compound of formula I in admixture with an agriculturally acceptable diluent or carrier.

The composition of the invention may of course include more than one compound of the invention.

In addition, the composition can comprise one or more additional active ingredients, for example compounds known to possess plant-growth regulant, herbicidal, fungicidal, insecticidal, acaricidal, antimicrobial or antibacterial properties. Alternatively the compound of the invention can be used in sequence with the other active ingredient.

The diluent or carrier in the composition of the invention can be a solid or a liquid optionally in association with a surface-active agent, for example a dispersing agent, emulsifying agent or wetting agent. Suitable surface-active agents include anionic compounds such as a carboxylate, for example a metal carboxylate of a long chain fatty acid: an N-acylsarcosinate; mono- or di-esters of phosphoric acid with fatty alcohol ethoxylates or alkyl phenol ethoxylates or salts of such esters; fatty alcohol sulfates such as sodium dodecyl sulfate, sodium octadecyl sulfate or sodium cetyl sulfate; ethoxylated fatty alcohol sulfates; ethoxylated alkylphenol sulfates; lignin sulfonates; petroleum sulfonates; alkyl-aryl sulfonates such as alkyl-benzene sulfonates or lower alkylnaphthalene sulfonates, e.g. butyl-naphthalene sulfonate; salts of sulfonated naphthalene-formaldehyde condensates; salts of sulfonated phenol-formaldehyde condensates; or more complex sulfonates such as the amide sulfonates, e.g. the sulfonated condensation product of oleic acid and N-methyl taurine; the dialkyl sulfosuccinates, e.g. the sodium sulfonate of dioctyl succinate; acid derivatives of alkyl glycosides and alkylpolyglycosides materials and their metal salts, e.g. alkyl polyglycoside citrate or tartrate materials; or mono-, di- and tri-alkyl esters of citric acid and their metal salts.

Nonionic agents include condensation products of fatty acid esters, fatty alcohols, fatty acid amides or fatty-alkyl- or alkenyl-substituted phenols with ethylene and/or propylene oxide; fatty esters of polyhydric alcohol ethers, e.g. sorbitan fatty acid esters; condensation products of such esters with ethylene oxide, e.g. polyoxyethylene sorbitan fatty acid esters; is alkyl glycosides, alkyl polyglycoside materials; block copolymers of ethylene oxide and propylene oxide; acetylenic glycols such as 2,4,7,9-tetramethyl-5-decyne-4,7-diol, ethoxylated acetylenic glycols; acrylic based graft copolymers; alkoxylated siloxane surfactants; or imidazoline type surfactants, e.g. 1-hydroxyethyl-2-alkylimidazoline.

Examples of a cationic surface-active agent include, for instance, an aliphatic mono-, di-, or polyamine as an acetate, naphthenate or oleate; an oxygen-containing amine such as an amine oxide, polyoxyethylene alkylamine or polyoxypropylene alkylamine; an amide-linked amine prepared by the condensation of a carboxylic acid with a di- or polyamine; or a quaternary ammonium salt.

The compositions of the invention can take any form known in the art for the formulation of agrochemicals, for example, a solution, an aerosol, a dispersion, an aqueous emulsion, a microemulsion, a dispersible concentrate, a dusting powder, a seed dressing, a fumigant, a smoke, a dispersible powder, an emulsifiable concentrate, granules or an impregnated strip. Moreover it can be in a suitable form for direct application or as a concentrate or primary composition which requires dilution with a suitable quantity of water or other diluent before application.

A dispersible concentrate comprises a compound of the invention dissolved in one or more water miscible or semi-water miscible solvents together with one or more surface active and/or polymeric material. Addition of the formulation to water results in the crystalisation of the active ingredient, the process being controlled by the surfactants and/or polymers resulting in a fine dispersion.

A dusting powder comprises a compound of the invention intimately mixed and ground with a solid pulverulent diluent, for example, kaolin.

An emulsifiable concentrate comprises a compound of the invention dissolved in a water-immiscible solvent which forms an emulsion or microemulsion on addition to water in the presence of an emulsifying agent.

A granular solid comprises a compound of the invention associated with similar diluents to those that may be employed in dusting powders, but the mixture is granulated by known methods. Alternatively it comprises the active ingredient absorbed or coated on a pre-formed granular carrier, for example, Fuller's earth, attapulgite, silica or limestone grit.

Wettable powders, granules or grains usually comprise the active ingredient in admixture with suitable surfactants and an inert powder diluent such as clay or diatomaceous earth.

Another suitable concentrate is a flowable suspension concentrate which is formed by grinding the compound with water or other liquid, surfactants and a suspending agent.

The concentration of the active ingredient in the composition of the present invention, as applied to plants is preferably within the range of 0.0001 to 1.0 per cent by weight, especially 0.0001 to 0.01 per cent by weight. In a primary composition, the amount of active ingredient can vary widely and can be, for example, from 5 to 95 per cent by weight of the composition.

The invention is generally applied to seeds, plants or their habitat Thus, the compound can be applied directly to the soil before, at or after drilling so that the presence of active compound in the soil can control the growth of fungi which may attack seeds. When the soil is treated directly the active compound can be applied in any manner which allows it to be intimately mixed with the soil such as by spraying, by broadcasting a solid form of granules, or by applying the active ingredient at the same time as drilling by inserting it in the same drill as the seeds. A suitable application rate is within the range of from 5 to 1000 g per hectare, more preferably from 10 to 500 g per hectare.

Alternatively the active compound can be applied directly to the plant by, for example, spraying or dusting either at the time when the fungus has begun to appear on the plant or before the appearance of fungus as a protective measure. In both such cases the preferred mode of application is by foliar spraying. It is generally important to obtain good control of fungi in the early stages of plant growth, as this is the time when the plant can be most severely damaged. The spray or dust can conveniently contain a pre- or post-emergence herbicide if this is thought necessary. Sometimes, it is practicable to treat the roots, bulbs, tubers or other vegetative propagule of a plant before or during planting, for example, by dipping the roots in a suitable liquid or solid composition. When the active compound is applied directly to the plant a suitable rate of application is from 0.025 to 5 kg per hectare, preferably from 0.05 to 1 kg per hectare.

In addition, the compounds of the invention can be applied to harvested fruits, vegetables or seeds to prevent infection during storage.

In addition, the compounds of the invention can be applied to plants or parts thereof which have been genetically modified to exhibit a trait such as fungal and/or herbicidal resistance.

In addition the compounds of the invention can be used to treat fungal infestations in timber and in public health applications. Also the compounds of the invention can be used to treat insect and fungus infestations in domestic and farm animals.

Compounds of the invention may be prepared, in known manner, in a variety of ways.

Compounds of formula Iai, i.e. compounds of general formula I where L is —CH(R¹)NHCH(R²)—, may be prepared according to reaction scheme 1. Compounds of formula II or their hydrochloride salts can be condensed with compounds of formula III and the intermediate reduced with a suitable reagent such as sodium cyanoborohydride to give compounds of formula Iai.

Compounds of formula II may be prepared by methods described in international application PCT/GB/99/00304.

Compounds of formula Iai may also be prepared by reacting compounds of formula IV with compounds of formula V in the same manner as above (Scheme 2).

Compounds of formula Iaii, i.e. compounds of general formula I where L is —CH(R¹)N(R³)CH(R²) and R³ is not hydrogen, may be prepared by reacting compounds of formula Iai with a base and R³Q, where Q is a leaving group such as a halogen. A suitable base is triethylamine (Scheme 3).

Compounds of formula Ib, i.e. compounds of general formula I where L is —N(R³)N(R⁴)C(═X)—, may be prepared according to reaction scheme 4 by reacting compounds of formula VI with compounds of formula VII, where Q is a leaving group such as halogen, preferably chlorine. A preferred base is triethylamine.

Compounds of formula Ic, i.e. compounds of general formula I where L is —C(═O)N(R³)CH(R¹), may be prepared by radical bromination of compounds of formula VIII, followed by reaction of these intermediates with compounds of formula IX according to scheme 5. Preferred reaction conditions are irradiation of a solution of VIII in carbon tetrachloride in the presence of N-bromosuccinimide and a catalytic amount of 2,2′-azobisisobutyronitrile, followed by addition of IX.

Compounds of formula Id, i.e. compounds of general formula I where L is —CH(R¹)O(C═O)—, may be prepared according to reaction scheme 6 by formation of the cesium salt of is compounds of formula XI, followed by reaction with compounds of formula X where Q is a suitable leaving group, such as chlorine.

Compounds of formula Ie, i.e. compounds of general formula I where L is —CH(R¹)OCH(R²)—, may be prepared by reaction of compounds of formula XII with a suitable base such as sodium hydride, followed by reaction of the resulting anion with compounds of formula X, where Q is a suitable leaving group such as halogen, according to reaction scheme 7.

Compounds of formula If, i.e. compounds of general formula I where L is —N(R³)C(═X)N(R⁴) and X is O or S, may be prepared according to reaction scheme 8 by reaction of compounds of formula XIII with compounds of formula XIV, where X is O or S, followed by the addition of compounds of formula XV. The order of addition of compounds of formulae XIII and XV may be reversed.

Compounds of formula Ig, i.e. compounds of general formula I where L is —C(R¹)═C(R²)C(═O)—, may be prepared according to reaction scheme 9 by reaction of compounds of formula XVI with compounds of formula XVII in the presence of sodium hydroxide.

Compounds of formula Ih, i.e. compounds of general formula I where L is —C(R¹)═N—N(R³)—, may be prepared by reacting compounds of formula XVIII with compounds of formula XIX according to reaction scheme 10.

Compounds of formula Ii, i.e. compounds of general formula I where L is —CH(R¹)N═C(R²)—, may be prepared according to reaction scheme 11 by reacting compounds of formula XX with a base, followed by reaction with compounds of formula XXI, where Q is a suitable leaving group, preferably chlorine. A suitable base is sodium hydride. Compounds of formula XX are known or can be prepared in a known manner by a is skilled chemist.

Compounds of formula Ij, i.e. compounds of general formula I where L is —O—N═C(R¹)—, may be prepared according to reaction scheme 12 by the reaction of compounds of formula XXII with a base, followed by reaction with compounds of formula XXI, where Q is a suitable leaving group, preferably chlorine. A suitable base is sodium hydride.

Compounds of formula XXII may be prepared according to reaction scheme 13.

Compounds of formula Imi, i.e. compounds of general formula I where L is —O—NHC(═O)—, may be prepared according to reaction scheme 14 by the reaction of compounds of formula XXIII with compounds of formula XXIV, where Q is a suitable leaving group.

Compounds of formula XXIV can be prepared from the corresponding hydroxy compounds by methods known to the skilled chemist. Compounds of formula XXIV can be isolated and used according to scheme 14 or generated in situ and used without isolation. A typical method, known to the skilled chemist, uses carbonyldiimidazole to generate compounds of formula XXIV in situ.

Compounds of formula XXIII can be prepared according to reaction scheme 15.

Compounds of formula Imii, i.e. compounds of general formula I where L is —N(R³)C(═O)— wherein R³ is not hydrogen, may be prepared by reaction of compounds of formula Imi with a base, followed by reaction with R³Q, where Q is a suitable leaving group, such as a halogen. A suitable base is potassium tert-butoxide (Scheme 16).

Other methods will be apparent to the chemist skilled in the art, as will be the methods for preparing starting materials and intermediates.

Collections of compounds of formula I may also be prepared in a parallel manner, either manually, automatically or semi-automatically. This parallel preparation may be applied to the reaction procedure, work-up or purification of products or intermediates. For a review of such procedures see by S. H. DeWitt in “Annual Reports in Combinatorial Chemistry and Molecular Diversity: Automated synthesis”, Volume 1, Verlag Escom 1997, pages 69 to 77.

Furthermore, compounds of the formula I may be prepared using solid-supported methods, where the reactants are bound to a synthetic resin. See for example: Barry A. Bunin in “The Combinatorial Index”, Academic Press, 1998 and “The tea-bag method” (Houghten, U.S. Pat. No. 4,631,211; Houghten et al., Proc. Natl. Acad. Sci, 1985, 82, 5131-5135).

The invention is illustrated in the following Examples. Structures of isolated, novel compounds were confirmed by NMR and/or other appropriate analyses.

EXAMPLE 1 N-(2-Chlorobenzyl)-N-{1-[3-chloro-5-(trifluorormethyl)-2-pyridyl]ethyl}amine (Compound 27)

α-Methyl-[3-chloro-5-(trifluoromethyl)-2-pyridyl]methylamine (0.2 g) was dissolved in trimethylorthoformate (10 ml) and triethylamine (0.22 ml) was added. After 5 minutes 2-chlorobenzaldehyde (0.26 g) was added and the resulting mixture stirred for 3.5 hours at room temperature to give a precipitate. Sodium cyanoborohydride (1.5 ml, 0.1 M solution in tetahydrofuran) and acetic acid (0.1 ml) were then added and the mixture stirred for 16 hours at room temperature. Brine (5 ml) and water (10 ml) were then added and the mixture stirred for 20 minutes. The phases were separated and the organic phase evaporated. The residue was purified by silica gel chromatography to give the title product, m.p. 117° C.

EXAMPLE 2 N-{[3-Chloro-5-(trifluoromethyl)-2-pyridyl]methyl}-N-[1-(3,4-difluorophenyl)-ethyl]amine (Compound 23)

Triethylamine (0.08 ml) and 1-(3,4-difluorophenyl)-1-ethagamine (0.11 g) were dissolved in trimethylorthoformate (10 ml), 3-Chloro-(5-trifluoromethyl)-pyridine-2-carboxaldehyde (0.15 g) was added and the solution stirred for 4 hours at room temperate. Sodium cyanoborohydride (1 ml, 0.1 M solution in tetahydrofuran) and acetic acid (0.07 ml) were then added and the mixture stirred for 16 hours at room temperature. Brine (5 ml) and water (10 ml) were then added and the mixture stirred for 20 minutes. The phases were separated and the organic phase evaporated. The crude material was purified by silica gel chromatography to give the title product, ¹H N.M.R (CDCl₃) δ(ppm) 1.4 (3H, d), 2.6 (1H, broad s), 3.8 (1H, q), 3.9 (1H, s), 7.1-7.3 (3H, m), 7.9 (1H, s) and 8.8 (1H, s).

EXAMPLE 3 Ethyl 2-[acetyl(benzyl)amino]-2-[3-chloro-5-trifluoromethyl)-2-pyridyl]acetate (Compound 4)

To a solution of compound 1 (0.6 mmol) in diethyl ether was added triethylamine (0.7 mmol) followed by acetyl chloride in diethyl ether (0.7 mmol). The mixture was stirred for two hours at room temperature before the addition of hydrochloric acid (8 ml, 2M). The organic phase was isolated, washed with sodium bicarbonate (10 ml), dried over magnesium sulfate and evaporated to yield the title compound, ¹H N.M.R (CDCl₃)(ppm) δ1.2 (3H, t), 2.3 (3H, s), 4.2 (2H, q), 4.8 (2H, q), 6.8-7.1 (6H, m), 7.5 (1H, s) and 8.5 (1H, s).

The following compounds of formula Iz (see Table A), i.e. compounds of general formula I where A¹ is 3-Cl-5-CF₃-2-pyridyl and L is —CH(R¹)N(R³)CH(R²)—, may be prepared by methods analogous to those of Examples 1, 2 and 3. The amine starting materials were obtained using methods described in international application PCT/GB/99/00304.

TABLE A Cmp R¹ R² R³ A² m.p./° C. 1 EtOC(═O)— H H phenyl oil 2 EtOC(═O)— H H 2-Cl-phenyl oil 3 EtOC(═O)— H H 3,4-methylenedioxyphenyl oil 4 EtOC(═O)— H MeC(═O)— phenyl oil 5 EtOC(═O)— H MeOCH₂C(═O)— phenyl oil 6 EtOC(═O)— H MeOC(═O)—C(═O)— phenyl 104-7 7 EtOC(═O)— H MeC(═O)— 2-Cl-phenyl  77-81 8 EtOC(═O)— H MeOCH₂C(═O)— 2-Cl-phenyl oil 9 EtOC(═O)— H MeOC(═O)—C(═O)— 2-Cl-phenyl 128-31 10 EtOC(═O)— H MeC(═O)— 3,4-methylenedioxyphenyl oil 11 EtOC(═O)— H MeOCH₂C(═O)— 3,4-methylenedioxyphenyl oil 12 EtOC(═O)— H MeOC(═O)—C(═O)— 3,4-methylenedioxyphenyl 106-9 13 H MeOC(═O)CH₂— H phenyl oil 14 H EtOC(═O)CH₂— H phenyl oil 15 H H H phenyl oil 16 H H H 2-Cl-6-F-phenyl oil 17 H Me H 2-Cl-phenyl oil 18 H Me H 2,6-diF-phenyl oil 19 H Me H

oil 20 H Me H 4-tolyl oil 21 H H H 2,5-diF-phenyll oil 22 H Me H 4-NO₂-phenyl oil 23 H Me H 3,4-diF-phenyl oil 24 H H H 2-Cl-phenyl oil 25 H H H 4-PhO-phenyl oil 26 H H H 2-NO₂-phenyl oil 27 Me H H 2-Cl-phenyl 117 28 Me H H 2-NO₂-phenyl 136 29 H Me H phenyl oil 30 H Me H 3-CF₃O-phenyl oil 31 H Me H 4-CF₃O-phenyl oil 32 H Me H

oil 33 H Me H 4-Cl-phenyl oil 34 H Me H 4-Br-phenyl oil 35 Me H H cyclohexyl oil 36 Me H H 2-F-phenyl oil 37 Me H H 4-Cl-phenyl oil 38 Me H H 2,5-diMeO-phenyl oil 39 Me H H 2-Cl-6-F-phenyl oil 40 Me H H 2-Br-phenyl oil 41 Me H H 3-CF₃O-phenyl oil 42 Me H H 4-MeS-phenyl oil 43 Me H H 2,5-xylyl oil 44 H H H cyclohexyl oil 45 H H H 3-Br-phenyl oil 46 H H H 4-Me₂N-phenyl oil 47 H H H 4-Cl-phenyl oil 48 H H H 2-F-phenyl oil 49 H H H 2,5-diMeO-phenyl oil 50 H H H 2-Br-phenyl oil 51 H H H 4-NO₂-phenyl oil 52 H H H 2,5-xylyl oil 53 H Me H

oil 54 H H H pentaF-phenyl oil

The ¹H N.M.R. or mass spectral data of those compounds in Table A which were not solid at room temperature are presented below.

Compound 1

¹H N.M.R (CDCl₃) δ (ppm) 1.2 (3H, t), 2.9 (1H broad s), 3.8 (1H, q), 4.2 (2H m), 5.0 (1H, s), 7.4-7.2 (5H, m), 7.9 (1H, s), 8.7 (1H, s).

Compound 2

¹H N.M.R (CDCl₃) δ (ppm) 1.2 (3H, t), 3.1 (1H, broad s), 4.0 (2H, q), 4.2 (2H, m), 5.1 (1H, s), 7.5-7.2 (4H, m), 8.0 (1H, s), 8.7 (1H, s).

Compound 3

¹H N.M.R (CDCl₃) δ (ppm) 1.2 (3H, t), 2.4 (1H, broad s), 3.8 (2H, q), 4.2 (2H, m), 5.0 (1H, s), 5.9 (2H, s), 6.74 (1H, d), 6.76 (1H, s), 6.83 (1H, s), 7.9 (1H, s), 8.7 (1H, s).

Compound 4

¹H N.M.R (CDCl₃) δ (ppm) 1.2 (3H, t), 2.3 (3H, s), 4.2 (2H, q), 4.8 (2H, q), 6.8-7.1 (6H, m), 7.5 (1H, s), 8.5 (1H, s).

Compound 5

m/z (APCI) 445 (M+H)⁺.

Compound 8

m/z (APCI) 479 (M+H)⁺.

Compound 10

m/z (APCI) 487 (M⁻).

Compound 11

m/z (APCI) 459 (M+H)⁺.

Compound 13

¹H N.M.R (CDCl₃) δ(ppm) 2.7 (1H, dd), 2.9 (1H, dd), 3.6 (3H, s), 3.9 (2H, s), 4.2 (1H, m), 7.3 (5H, m), 7.8 (1H, s), 8.8 (1H, m).

Compound 14

¹H N.M.R (CDCl₃) δ(ppm) 1.2 (3H, t), 2.7 (1H, dd), 2.8 (1h, dd), 3.9 (2H, s), 4.1 (2H, q), 4.2 (1H, m), 7.2-7.4 (5H, m), 7.8 (1H, s), 8.8 (1H, s).

Compound 15

¹H N.M.R (CDCl₃) δ(ppm) 4.2 (2H, s), 5.3 (2H, s), 7.3 (6H, m), 8.8 (1H, s), 8.9 (1H, s).

Compound 16

¹H N.M.R (CDCl₃) δ(ppm) 2.7 (1H, broad s), 4.05 (4H, s), 6.9-7.2 (3H, m), 7.8 (1H, s), 8.6 (1H, s).

Compound 17

¹H N.M.R (CDCl₃) δ(ppm) 1.4 (3H, d), 2.5 (1H, broad s), 3.9 (2H, m), 4.3 (1H, q), 7.1-7.3 (3H, m) 7.5 (1H, m) 7.8 (1H, s), 8.7 (1H, s).

Compound 18

¹H N.M.R (CDCl₃) δ(ppm) 1.5 (3H, d), 2.6 (1H, broads), 3.8 (1H, m), 4.0 (1H, m) 4.3 (1H, q), 6.8 (2H, m) 7.1 (1H, m) 7.8 (1H, s) 8.6 (1H, s).

Compound 19

¹H N.M.R (CDCl₃) δ(ppm) 1.4 (3H, d) 2.6 (1H, broad s), 3.8 (1H, q), 4.0 (2H, s), 4.3 (4H, s) 6.8 (2H, s), 6.9 (1H s), 7.9 (1H, s), 8.7 (1H, s).

Compound 20

¹H N.M.R (CDCl₃) δ(ppm) 1.5 (3H, d), 2.4 (3H, s), 2.8 (1H, broad s), 3.8 (1H, q), 4.0 (2H, m), 7.2 (2H, d), 7.3 (2H, d), 7.8 (1H, s), 8.7 (1H, s).

Compound 21

¹H N.M.R (CDCl₃) δ(ppm) 2.5 (1H, broad s), 4.0 (2H, s), 4.1 (2H, s), 6.8 (2H, m), 7.2 (1H, m), 7.8 (1H, s), 8.6 (1H, s).

Compound 22

¹H N.M.R (CDCl₃) δ(ppm) 1.4(3H, d), 2.5 (1H, broad s), 3.86 (2H, s), 3.9 (1H, m), 7.5 (2H, d), 7.8 (1H, s), 8.1 (2H, d), 8.7 (1H, s).

Compound 23

¹H N.M.R (CDCl₃) δ(ppm) 1.4 (3H, d), 2.6(1H, broad s), 3.8(1H, q), 3.9(1H, s), 7.1-7.3 (3H, m), 7.9(1H, s), 8.8 (1H, s).

Compound 24

¹H N.M.R (CDCl₃) δ(ppm) 4.1(4H, m), 4.4(1H, dd), 4.6(1H, dd), 6.5(1H, broads), 7.2-7.4(5H, m), 7.8 (1H, s), 8.6(1H, s).

Compound 25

¹H N.M.R (CDCl₃) δ(ppm) 3.9 (1H, dd), 4.2 (1H, dd), 4.4 (2H, m), 6.0 (1H, broad s), 6.9-7.0 (5H, m), 7.2-7.4 (4H, m), 8.0 (1H, s), 8.7 (1H, s).

Compound 26

¹H N.M.R (CDCl₃) δ(ppm) 4.3 (2H, m), 4.7 (2H, m), 7.0 (1H, broad s), 7.6 (1H, m), 7.7 (21, m), 7.9 (1H, s), 8.2 (1H, m), 8.6 (1H, s).

Compound 29

¹H N.M.R (CDCl₃) δ(ppm) 1.5 (3H, s), 2.6 (1H, broad s), 3.9 (1H, q), 4.0 (2H, s), 7.2-7.4 (5H, m), 7.8 (1H, s), 8.7 (1H, s).

Compound 30

¹H N.M.R (CDCl₃) δ(ppm) 1.4 (3H, d), 2.6 (1H, broad s), 3.8 (1H, q), 3.9 (2H, s), 4.0 (2H, s), 7.0(1H, m), 7.2-7.3 (3H, m), 7.8(1H, s), 8.7 (1H, s).

Compound 31

¹H N.M.R (CDCl₃) δ(ppm) 1.5 (3H, d), 2.7 (1H, broad s), 3.8 (1H, q), 6.5 (1H, m), 7.1 (2H, d), 7.4 (2H, d), 7.9 (1H, s), 8.8 (1H, s).

Compound 32

¹H N.M.R (CDCl₃) δ(ppm) 1.5 (3H, d), 1.8 (41, m), 2.8 (4H, m), 3.8 (1H, q), 4.0 (2H, s), 7.1 (3H, m), 7.9 (1H, s), 8.8 (1H, s).

Compound 33

¹H N.M.R (CDCl₃) δ(ppm) 1.42 (3H, d), 2.62 (1H, broad, s), 3.83 (1H, q), 3.92 (2H, s), 7.3 (4H, s), 7.82 (1H, s); 8.75 (1H, s).

Compound 34

¹H N.M.R (CDCl₃) δ(ppm) 1.42 (3H, d), 2.58 (1H, s, broad), 3.82 (1H, q), 3.92 (2H, s), 7.25 (2H, m), 7.45 (2H, m), 7.85 (1H, s), 8.72 (1H, s).

Compound 35

¹H N.M.R (CDCl₃) δ(ppm) selected peaks at 1.38(3H, d), 4.35 (1H, q), 7.85 (1H, s), 8.75 (1H, s).

Compound 36

¹H N.M.R (CDCl₃) δ(ppm) 1.38 (3H, d), 2.35 (1H, broad, s), 3.68 (2H, m), 4.42 (1H, q), 6.95 (1H, m), 7.05 (1H, m), 7.16 (1H, m), 7.32 (1H, m), 7.82 (1H, s), 8.75 (1H, s).

Compound 37

¹H N.M.R (CDCl₃) δ(ppm) selected peaks at 1.38 (3H, d), 3.56 (2H, m), 4.4 (1H, q), 7.88 (1H, s), 8.78 (1H, s).

Compound 39

¹H N.M.R (CDCl₃) δ(ppm) 1.3 (3H, d), 2.7 (1H, broad, s), 3.8 (2H, s), 4.4 (1H, q), 6.75 (1H, m), 6.98(2H, m), 7.72(1H, s), 8.55(1H, s).

Compound 40

¹H N.M.R (CDCl₃) δ(ppm) 1.41 (3H, d), 2.3 (1H, broad, s), 3.72 (2H, m), 4.25 (1H, q), 7.05-7.5 (4H, m), 7.85 (1H, s), 8.75 (1H, s).

Compound 41

¹H N.M.R (CDCl₃) δ(ppm) 1.38 (3H, d), 2.4 (1H s, broad), 3.6 (21, m), 4.4 (1H, q), 7.05-7.5 (4H, m), 7.88 (1H, s), 8.78 (1H, s).

Compound 42

¹H N.M.R (CDCl₃) δ(ppm) 1.38 (3H, d), 2.48 (3H, s), 3.6 (2H, m), 4.45 (1H, q), 7.2 (4H, m), 7.88 (1H, s), 8.78 (1H, s).

Compound 43

¹H N.M.R (CDCl₃) δ(ppm) 1.4 (3H, d), 2.25 (3H, s), 2.32 (3H, s), 2.5 (1H, broad, s), 3.58 (2H, m), 4.48 (1H, q), 6.9-7.08 (3H, m), 7.9 (1H, s), 8.78 (1H, s).

Compound 44

¹H N.M.R (CDCl₃) δ(ppm) selected peaks at 2.53 (2H, d), 4.1 (2H, s), 7.85 (1H, s), 8.75 (1H, s).

Compound 45

¹H N.M.R (CDCl₃) δ(ppm) selected peaks at 3.85 (1H, s), 4.1 (1H, s), 7.9 (1H, s), 8.75 (1H, s).

Compound 46

¹H N.M.R (CDCl₃) δ(ppm) selected peaks at 7.8 (1H, s), 8.68 (1H, s), 3.5 (1H, m), 3.9 (2H, m), 4.1 (1H, m).

Compound 47

¹H N.M.R (CDCl₃) δ(ppm) selected peaks at 3.86 (2H, s), 4.08 (2H, s), 7.90 (1H, s), 8.72(1H, s).

Compound 48

¹H N.M.R (CDCl₃) δ(ppm) selected peaks at 2.65 (1H, s, broad), 3.98 (2H, s), 4.15 (2H, s), 7.9 (1H, s), 8.75 (1H, s).

Compound 49

¹H N.M.R (CDCl₃) δ(ppm) selected peaks at 3.80 (3H, s), 3.85 (3H, s), 6.88 (2H, m), 7.06 (1H, m), 7.90 (1H, s), 8.72 (1H, s).

Compound 50

¹H N.M.R (CDCl₃) δ(ppm) selected peaks at 4.0 (2H, s), 4.1 (2H, s), 7.85 (1H, s), 8.70 (1H, s).

Compound 51

¹H N.M.R (CDCl₃) δ(ppm) selected peaks at 2.65 (1H, broad, s), 3.83 (2H, s), 4.0 (2H, s), 7.8 (1H, s), 8.65 (1H, s).

Compound 52

¹H N.M.R (CDCl₃) δ(ppm) selected peaks at 3.83 (2H, s), 4.18 (2H, s), 7.9 (1H, s), 8.75 (1H, s).

Compound 53

¹H N.M.R (CDCl₃) δ(ppm) 1.4 (3H, d), 2.5 (1H, broad s), 3.8 (1H, q), 3.9 (2H, s), 6.0 (2H, s), 6.8-6.9 (3H, m), 7.9 (1H, s), 8.7 (1H, s).

Compound 54

¹H N.M.R (CDCl₃) δ(ppm) selected peaks at 7.75 (1H, s), 8.80 (1H, s).

EXAMPLE 4 N′-1-[3-Chloro-5-(trifluoromethyl)-2-pyridyl-2,6-dichloro-1-benzenecarbohydrazide (Compound 102)

3-Chloro-5-trifluoromethyl)pyrid-2-ylhydrazine (0.32 g) was dissolved in dichloromethane (7 ml) and treated dropwise with 2,6-dichlorobenzoyl chloride (0.31 g) in dichloromethane (2 ml). Triethylamine (0.15 g) was then added and the reaction stirred at room temperature overnight. The organic solution was washed sequentially with sodium bicarbonate solution and brine and evaporated to give a solid. The residue was purified by trituration (dichloromethane) to give the title compound, m.p. 212-5° C.

The following compounds of formula Iy (see Table B), i.e. compounds of general formula I where L is —N(R³)NHC(═O)—, may be prepared by methods analogous to those of Example 4.

TABLE B Cmp A¹ R³ A² m.p./° C. 101 3-Cl-5-CF₃-pyridyl H 2-Cl-phenyl 168-70 102 3-Cl-5-CF₃-pyridyl H 2,6-diCl-phenyl 212-5 103 3-Cl-5-CF₃-pyridyl H 2-NO₂-phenyl 182-3 104 3-Cl-5-CF₃-pyridyl H 2,6-diMeO-phenyl 204-6 105 3-Cl-5-CF₃-pyridyl H 2-tolyl 168-9 107 3-Cl-5-CF₃-pyridyl H cyclopropyl 152-4 108 3-Cl-5-CF₃-pyridyl H cyclohexyl 111-4 109 3-Cl-5-CF₃-pyridyl Me 2,6-diCl-phenyl 219-20 110 3-Cl-5-CF₃-pyridyl Me 2-NO₂-phenyl 198-9 111 3-Cl-5-CF₃-pyridyl Me 2,6-diMeO-phenyl 234-6 112 3-Cl-5-CF₃-pyridyl Me 2-tolyl 202-4 113 3-Cl-5-CF₃-pyridyl Me 2-Cl-6-F-phenyl 207-8 115 3-Cl-5-CF₃-pyridyl Me cyclopropyl 159-60 116 3-Cl-5-CF₃-pyridyl Me cyclohexyl 216-9 117 5 Cl-3-CF₃-pyridyl H 2,6-diCl-phenyl 199-203 118 5-Cl-3-CF₃-pyridyl H 2-NO₂-phenyl 156-8 119 5-Cl-3-CF₃-pyridyl H 2,6-diMeO-phenyl 194-5 120 5-Cl-3-CF₃-pyridyl H 2-tolyl 180-1 121 5-Cl-3-CF₃-pyridyl H 2-Cl-6-F-phenyl 173-5 123 5-Cl-3-CF₃-pyridyl H cyclopropyl 143-5 124 5-Cl-3-CF₃-pyridyl H cyclohexyl 121 125 3-Cl-5-CF₃-pyridyl H 2,3,6-triF-phenyl 154-6 126 3-Cl-5-CF₃-pyridyl H 2-Cl-6-F-phenyl 192

EXAMPLE 5 N-2-(Phenylethyl)-3-chloro-5-(trifluoromethyl)-2-pyridinecarboxamide (Compound 206)

3-Chloro-(5-trifluoromethyl)pyridine-2-carboxaldehyde (0.15 g) was dissolved in carbon tetrachloride (10 ml), 2′-Azobisisobutyronitrile (0.002 g) and N-bromosuccinimide (0.16 g) were added and the mixture was heated to reflux using a sun lamp. After 45 minutes the solution was cooled down to 0° C. (R)-(+)-α-methylbenzylamine (0.09 g) in carbon tetrachloride (0.03 ml) was added and stirred for 20 minutes at 0° C., then for 3 hours at room temperature. The mixture was diluted with dichloromethane and washed with water. The organic layer was isolated, dried over magnesium sulphate and evaporated to give the crude compound. The crude material was purified by silica gel chromatography to give the title product, m.p. 88° C.

The following compounds of formula Ix (see Table C), i.e. compounds of general formula I where A¹ is 3-Cl-5-CF₃-2-pyridyl and L is —C(═O)NHCH(R¹)—, may be prepared by methods analogous to those of Example 5.

TABLE C Cmp R¹ A² m.p. (° C.) 201 H 2,6-diF-phenyl 137 202 Me 2,6-diF-phenyl  97 203 H 2-Cl-phenyl 100-7 204 H 2,6-diCl-phenyl 114-6 205 Me 2-Cl-phenyl 120 206 Me phenyl  88 207 Me 4-Cl-phenyl 129 208 Me 4-Br-phenyl 139 209 Me 3,4-diF-phenyl 127 210 Me

123 211 Me 4-CF₃O-phenyl  95 212 Me 3-CF₃O-phenyl 114 213 Me

125 214 Me

129 215 H 4-tolyl 113

EXAMPLE 6 [3-Chloro-5-(trifluoromethyl)-2-pyridyl]methyl 2-chlorobenzoate Compound 301

To a solution of 2-chlorobenzoic acid (0.1 g) in dimethylformamide was added cesium carbonate (0.1 g) and the resulting solution was stirred for 1 hour. 3-Chloro-2-(chloromethyl)-5-trifluoromethyl pyridine (0.14 g) was added and stirring was continued for a further 48 hours. The solution was diluted with diethyl ether (10 ml) and washed with water (10 ml). The organic phase was separated, dried and evaporated to give a crude product. Silica gel chromatography (petrol/diethyl ether 7:3) gave the title compound, ¹H N.M.R (CDCl₃) δ(ppm) 5.6 (2H, s), 7.3 (1H, m), 7.4 (2H, m) 7.87 (1H, s), 7.88 (1H, d) and 8.8 (1H, s).

The following compounds of formula Iw (see Table D), i.e. compounds of general formula I is where A¹ is 3-Cl-5-CF₃-2-pyridyl and L is —CH₂O(C═O), may be prepared by methods analogous to those of Example 6.

TABLE D Cmp A² m.p./° C. 301 2-Cl-phenyl oil 302 2,6-diCl-phenyl 93-5

EXAMPLE 7 [3-Chloro-5-(trifluoromethyl)-2-pyridyl]methyl(2,4-dichlorobenzyl) ether (Compound 401)

To a solution of 2,4-dichlorobenzyl alcohol (0.27 g) in tetrahydrofuran under nitrogen was added sodium hydride (1.1 equivalents) portionwise. The resulting solution was stirred at room temperature for 1 hour before the addition of 3-chloro-2)-chloromethyl)-5-trifluoromethyl pyridine (0.35 g) in tetrahydrofuran dropwise. The solution was then stirred at room temperature for 16 hours. The solution was treated with a tetrahydrofuran/methanol solution and the solvent then evaporated. The residue was partitioned between water and ethyl acetate, the organic phase was isolated, washed with brine, dried and evaporated to yield the crude product. Silica gel chromatography (petrol/ethyl acetate 95:5) furnished the title compound, ¹H N.M.R (CDCl₃) δ(ppm) 4.8 (2H, s), 4.9 (2H, s), 7.3 (1H, m), 7.4 (1H, m), 7.5(1H, m) 8.0(1H, s) and 8.8(1H, m).

The following compounds of formula Iv (see Table E), i.e. compounds of general formula I where A¹ is 3-Cl-5-CF₃-2-pyridyl and L is —CH₂OCH₂—, may be prepared by methods analogous to those of Example 7.

TABLE E Cmp A² m.p./° C. 401 2,4-diCl-phenyl oil 402 2,6-diCl-phenyl oil

The ¹H N.M.R. data of those compounds in Table E which were not solid at room temperature are presented below.

Compound 402

¹H N.M.R (CDCl₃) δ(ppm) 4.9 (2H, s), 5.0 (2H, s), 7.2 (1H, m), 7.3 (2H, m), 8.0 (1H, s), 8.8 (1H, s).

EXAMPLE 8 N-[2-Chloro-5-(tifluoromethyl)-2-pyridyl]-N′-(2,6-dichlorophenyl)urea (Compound 501)

A solution of triphosgene (1.1 g) in dichloromethane (20 ml) was added over 30 minutes at room temperature to a stirred solution of 2-amino-3-chloro-5-(trifluoromethyl)pyridine (1.96 g) and triethylamine (2 ml) in dichloromethane (35 ml). After 15 minutes a solution of 2,6-dichloroaniline (1.62 g) and triethylamine (2 ml) in dichloromethane (20 ml) was added rapidly and the resulting mixture stirred for 30 minutes before solvent evaporation. The residue was suspended in ethyl acetate and the solid filtered off. The filtrate was washed with potassium hydrogen sulfate solution, sodium bicarbonate solution and then brine. Drying (MgSO₄) and solvent evaporation yielded the crude product, which was purified by silica gel chromatography to give the title compound, m.p. 155-8° C.

The following compounds of formula Iu (see Table F), i.e. compounds of general formula I where A¹ is 3-Cl-5-CF₃-2-pyridyl and L is —NHC(═O)NH—, may be prepared by methods analogous to those of Example 8.

TABLE F Cmp A² m.p./° C. 501 2,6-diCl-phenyl 155-8 502 phenyl 173-5 503 2-NO₂-phenyl 178-80

EXAMPLE 9 3-[3-Chloro-5-(trifluoromethyl)-2-pyridyl]-1-(2-nitrophenyl)-2-propen-1-one (Compound 601)

Sodium hydroxide (0.55 g) was dissolved in water (5 ml) and the resulting solution was diluted with ethanol (3 ml). 2-Nitroacetophenone (1.8 g) was added at 20° C., and the solution was stirred for 5 minutes. 3-Chloro-5-(trifluoromethyl)pyridine-2-carboxaldehyde (2.25 g) was added and stirring was continued for 16 hours. The solution was acidified with acetic acid, the organic layer separated, dried over magnesium sulfate, filtered and evaporated to give a brown oil. Silica gel column chromatography, followed by recrystallisation (petrol) afforded the title compound, 88-9° C.

EXAMPLE 10 3-Chloro-5-(trifluoromethyl)-2-pyridinecarbaldehyde 2-(2-nitrophenyl)hydrazone (Compound 701)

A mixture of 3-chloro-5-(trifluoromethyl)pyridine-2-carboxaldehyde (1.05 g) and 2-nitrophenylhydrazine (0.76 g) in ethanol (75 ml) was heated at reflux for 2.5 hours and then allowed to cool to room temperature overnight. The resulting orange solid was isolated by filtration and recrystallised (petrol) to afford the title compound as admixture of isomers, m.p. 127-35° C.

EXAMPLE 11 [3-Chloro-5-(trifluoromethyl)-2-pyridyl](diphenylmethylene)amino]methyl cyanide (Compound 803)

To a suspension of 60% sodium hydride (4.0 g) in dimethylformamide under a nitrogen atmosphere at 0° C. was added a solution of [(diphenylmethylene)amino]methyl cyanide (11.1 g) in dimethylformamide dropwise, whilst maintaining the temperature between 0° C. and 2° C. The solution was stirred at 0° C. for 1 hour. 2,3-Dichloro-5-trifluoromethylpyridine (7 ml) in dimethylformamide was added dropwise and the mixture stirred for 30 minutes at 0° C. before warming to ambient temperature over 3 hours. The mixture was cooled to 10° C., ethanol (3 ml) added and the solution stirred for 15 minutes. The reaction mixture was then poured as a thin stream into a vigorously stirred mixture of diethyl ether (500 ml) and ammonium chloride solution (500 ml). The organic layer was separated and washed with ammonium chloride solution (2×150 ml), dried, filtered and evaporated to give a residue.

Silica gel chromatography (diethyl ether:petrol 5:95) gave the title product as a pale brown solid, m.p. 108-10° C.

The following compounds of formula It (see Table G), i.e. compounds of general formula I where A¹ is 3-Cl-5-CF₃-2-pyridyl, L is —CH(R¹)N═C(Ph)—, and A² is phenyl may be prepared by methods analogous to those of Example 11.

TABLE G Cmp R¹ m.p./° C. 801 CH₂CN 82-4 802 CO₂Et oil 803 CN 108-10

The mass spectral data of the compound in Table G which was not solid at room temperature is presented below.

Compound 802

m/z (EI) 373 (M⁺ —CO₂Et)

EXAMPLE 12 1-Biphenylyl-1-ethanone O-1-[3-chloro-5-(trifluoromethyl)-2-pyridyl] oxime (Compound 936)

To 4-acetylbiphenyl oxime (2.5 g) in dimethylformamide (13 ml) under a nitrogen atmosphere was added sodium hydride (0.5 g) portionwise with cooling. The resulting mixture was stirred at 40° C. for 20 minutes until the formation of a suspension occurred. 2,3-Dichloro-5-(trifluoromethyl)pyridine (2.5 g) in dimethylformamide (7 ml) was then added and the resulting mixture stirred for 18 hours at room temperature. The mixture was treated with isopropanol (2 ml) and stirred for 5 minutes before pouring into an ice water/brine solution (300 ml). The resulting precipitate was extracted with diethyl ether (2×125 ml), the organics washed with water, dried, filtered and evaporated to give a solid which on trituration (diethyl ether) and recrystallisation (toluene) yielded the title compound, m.p. 122° C.

Preparation of Starting Material

-   -   4-Acetylbiphenyl Oxime     -   To a suspension of 4-acetylbiphenyl (25.4 g) in ethanol (230 ml)         and water (4 ml) under a nitrogen atmosphere was added         hydroxylamine hydrochloride (14.5 g) in water (25 ml) followed         by 50% aqueous potassium hydroxide solution (40 g). The         resulting mixture was heated at reflux for 18 hours and then         cooled to room temperature. The mixture was added to ice/water         (500 ml) and acidified to pH 2 to give a precipitate. The solid         was filtered off, washed with water until the washings were at         pH 6 and then recrystallised from ethanol to give the title         compound.

following compounds of formula Is (see Table H), i.e. compounds of general formula I where L is —O—N═(R¹)—, may be prepared by methods analogous to those of Example 12. The crossed bond in Is indicates that the compounds may exist as cis or trans isomers about the double bond. Isolation of both isomers was possible for some compounds.

TABLE H Cmp A¹ R¹ A² m.p. (° C.) 901 3-Cl-5-CF₃-2-pyridyl Me 2-Cl-phenyl  96-7 902 3-Cl-5-CF₃-2-pyridyl H 4-pyridyl 205-6 903 3-Cl-5-CF₃-2-pyridyl Me 3-(2-Cl-4-CF₃-phenoxy)phenyl  65-7 904 3-Cl-5-CF₃-2-pyridyl H 2-Cl-6-F-phenyl 119-23 905 3-Cl-5-CF₃-2-pyridyl H 2,6-diCl-phenyl 136-7 906 3-Cl-5-CF₃-2-pyridyl Me 1-Me-2-pyrolyl  88-9 907 3-Cl-5-CF₃-2-pyridyl Me 2-tolyl oil 908 3-Cl-5-CF₃-2-pyridyl Me 2-tolyl oil 909 3-Cl-5-CF₃-2-pyridyl Me 3-CF₃-phenyl oil 910 3-Cl-5-CF₃-2-pyridyl Me 2-CF₃-phenyl oil 911 3-Cl-5-CF₃-2-pyridyl Me

oil 912 3-Cl-5-CF₃-2-pyridyl tBu 2-pyridyl oil 913 3-Cl-5-CF₃-2-pyridyl Me 2-thienyl oil 914 3-Cl-5-CF₃-2-pyridyl H 4-MeO-phenyl oil 915 3-Cl-5-CF₃-2-pyridyl Me 2,4-xylyl oil 916 3-Cl-5-CF₃-2-pyridyl H 6-Me-2-pyridyl oil 917 3-Cl-5-CF₃-2-pyridyl Me 2-naphthyl oil 918 3-Cl-5-CF₃-2-pyridyl Me 1-naphthyl oil 919 3-Cl-5-CF₃-2-pyridyl H 4-EtO-phenyl oil 920 3-Cl-5-CF₃-2-pyridyl H 2-tolyl oil 921 3-Cl-5-CF₃-2-pyridyl H 2-MeO-phenyl oil 922 3-Cl-5-CF₃-2-pyridyl Et phenyl oil 923 3-Cl-5-CF₃-2-pyridyl H 3-NO₂-phenyl 116-8 924 3-Cl-5-CF₃-2-pyridyl CF₃ 2-tolyl oil 925 3-Cl-5-CF₃-2-pyridyl (EtO)₂P(═O)— cyclohexyl oil 926 3-Cl-5-CF₃-2-pyridyl —CN phenyl  76 927 3-Cl-5-CF₃-2-pyridyl Me phenyl oil 928 3-Cl-5-CF₃-2-pyridyl H 2-NO₂-phenyl oil 929 3-Cl-5-CF₃-2-pyridyl H 2-Cl-phenyl  87 930 3-Cl-5-CF₃-2-pyridyl H 3-tolyl oil 931 3-Cl-5-CF₃-2-pyridyl H 3-pyridyl oil 932 3-Cl-5-CF₃-2-pyridyl H 3-pyridyl 137-8 933 3-Cl-5-CF₃-2-pyridyl H 1-naphthyl  85-90 934 3,5-diCl-2-pyridyl Me 2-Cl-phenyl 127 935 3,5-diCl-2-pyridyl Me 2-Cl-phenyl  70-1 936 3-Cl-5-CF₃-2-pyridyl Me biphenylyl 122 937 3-Cl-5-CF₃-2-pyridyl —CN 2,6-diCl-phenyl 128-9 938 3-Cl-5-CF₃-2-pyridyl —CN 2,6-diCl-phenyl  71-2 939 3-Cl-5-CF₃-2-pyridyl —CN 2-CN-phenyl 139-43 940 3-Cl-5-CF₃-2-pyridyl —CN 2-Cl-phenyl  83-4 941 3-Cl-5-CF₃-2-pyridyl —CN 2-Cl-phenyl  88 942 3-Cl-5-CF₃-2-pyridyl Me 2-MeSO₂-phenyl oil 943 3-Cl-5-CF₃-2-pyridyl Ph 2-naphthyl oil 944 3-Cl-5-CF₃-2-pyridyl Me 6-MeO-2-naphthyl oil 945 3-Cl-5-CF₃-2-pyridyl Me 4-F-1-naphthyl oil 946 3-Cl-5-CF₃-2-pyridyl Me 4-cyclohexyl-phenyl oil 947 3-Cl-5-CF₃-2-pyridyl Me

oil 948 3-Cl-5-CF₃-2-pyridyl Pr 4-Cl-phenyl oil 949 3-Cl-5-CF₃-2-pyridyl Me cyclohexyl oil 950 3-Cl-5-CF₃-2-pyridyl Me 4-PhO-phenyl oil 951 3-Cl-5-CF₃-2-pyridyl Me 2,5-diMe-3-furyl oil 952 3-Cl-5-CF₃-2-pyridyl Me 3,5-diMe-isothiazol-4-yl oil 953 3-Cl-5-CF₃-2-pyridyl Et 2,4-diCl-phenyl oil 954 3-Cl-5-CF₃-2-pyridyl Me 2,3-diCl-phenyl oil 955 3-Cl-5-CF₃-2-pyridyl —CN 2-pyridyl oil 956 3-Cl-5-CF₃-2-pyridyl CF₃ 2-thienyl oil 957 3-Cl-5-CF₃-2-pyridyl Me 4-pyridyl oil 958 3-Cl-5-CF₃-2-pyridyl 4-Cl-phenyl 4-Cl-phenyl oil

¹H N.M.R or mass spectral data of those compounds in Table H which were not solid at room temperature are presented below.

Compound 907

¹H N.M.R (CDCl₃) δ (ppm) 2.4 (6H, s), 7.2-7.4 (4H, m), 7.95 (1H, s), 8.45 (1H, s).

Compound 908

¹H N.M.R (CDCl₃) δ (ppm) 2.3 (3H), 2.4 (3H0, 7.1 (1H), 7.3 (3H, m), 7.8 (1H), 8.45 (1H).

Compound 909

m/z (EI) 382 (M⁺).

Compound 910

¹H N.M.R (CDCl₃) δ (ppm) 2.5 (3H), 7.45 (1H, d), 7.5-7.7 (2H, m), 7.75 (1H, d), 8.0 (1H, d), 8.5 (1H, d).

Compound 911

¹H N.M.R (CDCl₃) δ (ppm) 0.8 (t), 1.15 (d), 1.4 (quintet), 2.0 (s), 23 (s), 3.65 (dd), 7.7 (m), 7.95 (m).

Compound 912

m/z (EI) 357 (M⁺).

Compound 913

m/z (EI) 320 (M⁺).

Compound 914

m/z (EI) 330 (M⁺).

Compound 915

m/z (EI) 342 (M⁺).

Compound 916

m/z (EI) 315 (M⁺).

Compound 917

m/z (EI) 364 (M⁺).

Compound 918

m/z (EI) 364 (M⁺).

Compound 919

m/z (EI) 344 (M⁺).

Compound 920

¹H N.M.R (CDCl₃) δ (ppm) 2.35 (s), 2.5 (s), 7.4 (d), 7.8 (m), 7.9 (d).

Compound 921

¹H N.M.R (CDCl₃) δ (ppm) 3.9 (3H, m), 6.9-7.05 (2H, m), 7.5-7.75 (2H, m), 7.95 (1H, d), 8.0 (1H, d), 8.5 (1H), 9.1 (1H).

Compound 922

m/z (EI) 328 (M⁺).

Compound 924

m/z (EI) 382 (M⁺).

Compound 925

¹H N.M.R (CDCl₃) δ (ppm) 1.3 (m), 2.7 (m), 4.2 (m), 7.75 (d), 7.95 (d).

Compound 927

m/z (EI) 314 (M⁺).

Compound 928

m/z (EI) 345 (M⁺).

Compound 930

¹H N.M.R (CDCl₃) δ (ppm) 2.35 (d), 7.25 (m), 7.5 (d), 7.9 (d), 8.5 (d), 8.65 (s).

Compound 931

m/z (EI) 301 (M⁺).

Compound 942

¹H N.M.R (CDCl₃) δ (ppm) 2.6 (3H, s), 3.05 (3H, s), 8.0 (5H, m), 8.5 (1H, s).

Compound 943

¹H N.M.R (CDCl₃) δ (ppm) 7.4-7.6 (7H, m), 7.8-8.0 (6H, m), 8.5 (1H, d).

Compound 944

m/z (EI) 393 (M⁺).

Compound 945

¹H N.M.R (CDCl₃) δ (ppm) 2.7 (3H, s), 7.15 (1H, dd), 7.5-7.65 (3H, m), 7.95 (1H, d), 8.1-8.25 (2H, m), 8.5 (1H, d).

Compound 946

m/z (EI) 396 (M⁺).

Compound 947

m/z (EI) 368 (M⁺).

Compound 948

m/z (EI) 376 (M⁺).

Compound 949

¹H N.M.R (CDCl₃) δ (ppm) 0.1-1.5 (5H, m), 1.7-1.9 (5H, m), 2.6 (1H, t), 8.0 (1H, m), 8.55 (1H, m).

Compound 950

m/z (EI) 406 (M⁺).

Compound 951

m/z (EI) 332 (M⁺).

Compound 952

m/z (EI) 349 (M⁺).

Compound 953

¹H N.M.R (CDCl₃) δ (ppm) 1.4 (3H, t), 3.0 (2H, q), 7.2 (3H, t) isomer, 7.3 (1H, d), 7.55 (1H, dd), 8.0 (1H, d, m), 8.55 (1H, d, m).

Compound 954

¹H N.M.R (CDCl₃) δ (ppm) 2.5 (3H, m), 7.2-7.4 (2H, m), 7.5 (1H, d), 7.9 (1H), 8.4 (1H).

Compound 955

¹H N.M.R (CDCl₃) δ (ppm) 2.6 (s), 4.8 (s), 7.25 (t), 7.5 (dd), 7.9 (m), 8.05 (d), 8.15 (d), 8.5 (s), 8.8 (d).

Compound 956

m/z (EI) 374 (M⁺).

Compound 957

m/z (EI) 314 (M⁺).

Compound 958

¹H N.M.R (CDCl₃) δ (ppm) 7.35-7.6 (8H, m), 7.9 (1H), 8.5 (1H).

EXAMPLE 13 N-(3-Chloro-5-trifluoromethyl-2-pyridyloxy)-1-naphthalenecarboxamide (Compound 1012)

A mixture of 1-naphthoic acid (0.46 g) and carbonyldiimidazole (0.44 g) in tetrahydrofuran (40 ml) was stirred for 16 hours under a nitrogen atmosphere. The product from stage b) (0.57 g) was then added, and the mixture stirred for 5 days. The solution was poured into saturated brine solution and the organic portion extracted with ethyl acetate (x3), dried (MgSO₄), filtered and evaporated. The residue was purified by silica gel chromatography (ethyl acetate/petrol) and triturated (diisopropyl ether) to give the title product, m.p. 198-9° C.

Preparation of Starting Materials

-   a)     2-{[3-Chloro-5-(trifluoromethyl)-2-pyridyl]oxy}-1,3-isoindolinedione     -   2,3-Dichloro-5-trifluoromethylpyridine (50.0 g) was added over 5         minutes to a stirred solution of N-hydroxyphthalimide (37.5 g)         and triethylanine (25.8 g) in acetone (750 ml). The mixture was         refluxed for 8 hours and allowed to stand at room temperature         for 16 hours. The solution was filtered and the filtrate         evaporated to yield a solid which was partitioned between ethyl         acetate and sodium bicarbonate solution. The organic fraction         was isolated and the aqueous material re-extracted using further         portions of ethyl acetate. The combined organic extracts were         washed with water, dried, filtered and evaporated to give the         crude product. The residue was triturated with diisopropyl ether         to furnish the title compound as a white solid. -   b) O-[3-Chloro-5-(trifluoromethyl)-2-pyridyl]hydroxylamine     -   Hydrazine monohydrate (1.7 g) was added to a solution of the         product from stage a) (11.3 g) in tetrahydrofuran (200 ml) and         the mixture stirred for 16 hours. The mixture was then filtered         and the residual solid washed with a small volume of         tetrahydrofuran and ethyl acetate, then four times with a 0.02M         solution of sodium hydroxide saturated with sodium chloride. The         combined aqueous layers were extracted with dichloromethane (x2)         and the combined organic extracts dried, filtered and evaporated         to give the title compound.

EXAMPLE 14 N-(3-Chloro-5-trifluoromethyl-2-pyridyloxy)-N-methyl-1-naphthalenecarboxamide (Compound 1017)

Iodomethane (0.82 g) was added to a stirred solution of the product from Example 13 (Compound 1012) (1.93 g) and potassium tert-butoxide (0.61 g) in tetahydrofuran (50 ml). The reaction mixture was stirred for 48 hours. The solvent was evaporated and the residue partitioned between ethyl acetate and saturated aqueous ammonium chloride. The aqueous layer was separated and extracted with 3 portions of ethyl acetate. The combined organic phases were dried, filtered and evaporated to give a residue which was purified by silica gel chromatography (ethyl acetate/petrol) to give the title compound, m/z (EI) 380 (M⁺).

The following compounds of formula Ir (see Table J), i.e. compounds of general formula I where A¹ is 3-Cl-5-CF₃-2-pyridyl and L is —O—N(R³)C(═O)—, may be prepared by methods analogous to those of Examples 13 and 14.

TABLE J Cmp R³ A² m.p. (° C.) 1001 H 5-Me-2-pyrazinyl 202-6 1002 H 4-tolyl 190-3 1003 H 2-Cl-4-CF₃-pyrimidin-5-yl 204-5 1004 H 4-Cl-phenyl 191-3 1005 H 2-NO₂-5-(2-Cl-4-CF₃-phenoxy)-phenyl 168-70 1006 H 3,5-diMe-4-isoxazolyl 108-11 1007 H 2,4-diMe-5-thiazolyl 152-5 1008 H 4,6-diMeO-2-(α,α-diMe-4-Cl-benzyl)- 124-5 pyrimidin-5-yl 1009 H 5-(3,5-diCl-phenoxy)-2-furyl 120-2 1010 H 6-MeO-3-pyridyl 157-9 1011 H 2-naphthyl 180 1012 H 1-naphthyl 198-9 1013 H 2-Cl-phenyl 170 1014 H 3-quinolinyl 238-9 1015 H

oil 1016 H 4-morpholinyl-3-NO₂-phenyl 217-8 1017 Me 1-naphthyl oil 1018 H 1-naphthyl 218-20 1019 H 2,6-diCl-phenyl 246-7

The mass spectral data of the compounds in Table J which were not solid at room temperature are presented below.

Compound 1015

m/z (EI) 412 (M⁺).

Compound 1017

m/z (EI) 380 (M⁺).

EXAMPLE 15 2-Methyl-1,2,3,4-tetrahydro-1-naphthalenone O-1-[3-chloror-5-(trifluoromethyl)-2-pyridyl]oxime (Compound 1101)

The starting material (0.58 g) was dissolved in tetrahydrofuran (5 ml) and to this was added potassium tert-butoxide (0.42 g) dissolved in tetrahydrofuran (5 ml). The mixture was stirred overnight and a solution of 2,3-dichloro-5-trifluoromethyl pyridine (0.72 g) in tetrahydrofuran (2 ml) was added. The mixture was stirred for 48 hours at room temperature, then the solvent was evaporated. The residue was partitioned between ethyl acetate and water. The organic layer was isolated, dried, filtered and evaporated to yield the title product as a light yellow gum, m/z (EI) 354 (M⁺).

-   a) 2-Methyl-1,2,3,4-tetrahydro-1-naphthalenone oxime     -   To a solution of 2-methyl-1-tetralone (3.20 g) in methanol         (5 ml) was added hydroxylamine hydrochloride (1.81 g) in         methanol (15 ml) and triethylamine (2.63 g). The mixture was         stirred at 65° C. for 5 hours, allowed to cool and stand at room         temperature for 16 hours. The solvent was evaporated and water         added to the residue. The product was extracted with ethyl         acetate (3 portions) and the combined extracts were dried,         filtered and evaporated to give an orange oil. On standing this         separated into two layers. The top layer was removed and the         bottom layer slowly solidified to give the title product as an         orange solid.

The following compounds of formula Iq (see Table K), i.e. compounds of general formula I where A¹ is 3-Cl-5-CF₃-2-pyridyl and L is —O—N═C(R¹)—, wherein R¹ and A², together with the interconnecting atoms forms a 5- or 6-membered ring, may be prepared by methods analogous to those of Example 15.

TABLE K Cmp R^(Z) m.p. (° C.) 1101

oil 1102

oil 1103

oil 1104

oil 1105

oil 1106

oil 1107

oil 1108

oil 1109

oil 1110

oil

Those compounds in Table K which do not have discrete melting points have the following characteristic mass spectral data.

Compound 1101

m/z (EI) 354 (M⁺).

Compound 1102

m/z (EI) 370 (M⁺).

Compound 1103

m/z (EI) 385 (M⁺).

Compound 1104

m/z (EI) 342 (M⁺).

Compound 1105

m/z (EI) 376 (M⁺).

Compound 1106

m/z (EI) 358 (M⁺).

Compound 1107

m/z (EI) 346 (M⁺).

Compound 1108

m/z (EI) 370 (M⁺).

Compound 1109

m/z (EI) 355 (M⁺).

Compound 1110

m/z (EI) 389 (M⁺).

EXAMPLE 16 2-{[2-(3-Bromo-4-methoxyphenyl)-1H-1-imidazolyl]methyl}-3-chloro-5-(trifluoromethyl)pyridine (Compound 1201)

To a solution of 2)-3-bromo-4-methoxyphenyl)-1H-imidazole (0.5 g) in tetrahydrofuran was added sodium hydride (0.08 g). After 30 minutes 3-chloro-2-(chloromethyl)-5-trifluoromethyl pyridine (0.46 g) was added and the solution heated until the reaction was complete. The reaction mixture was cooled, poured onto water and the organic phase extracted using dichloromethane, dried and evaporated to yield the crude product as an orange gum. Silica gel column chromatography yielded a gum which was further treated with diisopropyl ether and filtered. Evaporation of the filtrate afforded the title compound, m/z (APCI) 445 (M⁻).

2-(3-Bromo-4-methoxyphenyl)imidazole was synthesised from 3-bromo-4-methoxybenzonitrile using a method known to the skilled chemist.

Test Example

Compounds were assessed for activity against one or more of the following:

-   -   Phytophthora infestans: late tomato blight     -   Plasmopara viticola: vine downy mildew     -   Erysiphe graminis f. sp. tritici: wheat powdery mildew     -   Pyricularia oryzae: rice blast     -   Leptosphaeria nodorum: glume blotch

Aqueous solutions or dispersions of the compounds at the desired concentration, including a wetting agent, were applied by spray or by drenching the stem base of the test plants, as appropriate. After a given time, plants or plant parts were inoculated with appropriate test pathogens before or after application of the compounds as appropriate, and kept under controlled environmental conditions suitable for maintaining plant growth and development of the disease. After an appropriate time, the degree of infection of the affected part of the plant was visually estimated. Compounds are assessed on a score of 1 to 3 where 1 is little or no control, 2 is moderate control and 3 is good to total control. At a concentration of 500 ppm (w/v) or less, the following compounds scored 2 or more against the fungi specified.

-   Phytophthora infestans: 49, 102, 119, 126, 202, 214, 215, 601, 902,     912, 927, 953, 1101 and 1102. -   Plasmopara viticola: 7,9, 10, 12, 102, 109, 126, 214, 215, 601, 901,     907, 914, 915, 921, 926-30, 958, 1001 and 1013. -   Erysiphe graminis f. sp. tritici: 501, 901, 906, 913-5, 923,     926-931, 933, 935, 936, 948-50, 952, 954, 1008, 1102, 1104, 1107 and     1108. -   Pyricularia oryzae: 7, 9, 11, 17, 126, 901, 906, 907, 913, 922, 923,     926-31, 937, 938, 939 and 1001. -   Leptosphaeria nodorum: 23, 51, 53, 126, 207, 208, 906, 923, 926,     929, 933, 1007 and 1109. 

1. A method of combating plant fungi at a locus infested or liable to be infested therewith, which comprises applying to the locus a sufficient amount of a phytopathogenie fungicide to combat said plant fungi, said phytopathogenic fungicide comprising a compound of general formula I or salts thereof;

where A¹ is 3-Cl-5-CF₃-2-pyridyl; A² is optionally substituted heterocyclyl or optionally substituted carbocyclyl; excepted where L is —N(R₃)N(R₄)C(═O)— or —CH₂OCH₂—, then A₂ can not be a heterocyclyl containing N or O; L is a 3-atom linker of formula —N(R₃)N(R₄)C(═X)—; wherein A¹ is attached to the left hand side of linker L; where R¹ and R², which may be the same or different, are R^(b), cyano, nitro, halogen, —OR^(b), —SR^(b) or optionally substituted amino; R³ and R⁴, which may be the same or different, are R^(b), cyano or nitro; or any R¹, R², R³ or R⁴ group, together with the interconnecting atoms, can form a 5- or 6-membered ring with any other R¹, R², R³ or R⁴, or any R¹, R², R³ or R⁴ group, together with the interconnecting atoms can form a 5- or 6-membered ring with A²; X is oxygen, sulfur, N—OR^(b), or N—(R^(b))₂; and Y is halogen, —OR^(b), —SR^(b), —N(R^(b))₂, —NR^(b)(OR^(b)) or NR^(b)N(R^(b))₂; wherein R^(b) is alkyl, alkenyl, alkynyl, carbocyclyl or heterocyclyl, each of which may be substituted; or hydrogen or acyl, or two adjacent R^(b) groups together with the nitrogen atom to which they are attached may form a 5- or 6-membered ring.
 2. A fungicide composition comprising at least one compound as recited in claim 1 in admixture with an agriculturally acceptable diluent or carrier. 